Recently, electronic components of computers and word processors have been reaching still higher levels of integration. All manufacturing processes, from those that produce integrated circuit devices such as IC and LSI in instruments or storage device peripherals such as FD and HDD to those that produce semiconductor wafer starting materials, and patterning, semiconductor chip manufacture and semiconductor production, are now required to be carried out in clean rooms in order to improve the reliability of the products.
In the past, sufficient time has been available for installing filters in new clean rooms in factories. Gaps around filters were therefore sealed off from the outside atmosphere by a condensation curing type silicone sealant that cures at room temperature, or an addition curing type silicone gel that cures at room temperature (Tokkai Sho 62-34978, Official Gazette).
As ventilation filters in clean rooms have a fine mesh, they tend to clog easily with dirt and have to be frequently replaced.
According to the aforesaid conventional method, however, curing takes time, so several days are required for filter installation. This means that work in a clean room that is already operating must be interrupted for several days.
Moreover, as filters are embedded in the ceiling or the floor, sealing work often has to be performed in narrow or dark locations. This may lead to imperfections when gaps are filled with sealing materials so that it impossible to maintain the required degree of cleanliness.
The inventors, as a result of extensive studies of the aforesaid disadvantages, discovered that by using an anti-dust gel sheet having a reinforcing material as an intermediate layer, the penetration of this sheet lying within specified limits after curing, filter replacement in dark or narrow locations could be simplified, and filter replacement could be performed in a short time period.